Tree stand



FIG. 1 is a perspective view of the tree stand showing the new design;

FIG. 2 is a front view;

FIG. 3 is a rear view;

FIG. 4 is a right side view;

FIG. 5 is a left side view;

FIG. 6 is a top view; and,

FIG. 7 is a bottom view.

The ornamental design for a tree stand, as shown and described.